When looking at some ways to optimize the performance of my Windows Store application, I stumbled over the following property: DebugSettings.IsOverdrawHeatMapEnabled.
This property helps you determine where and when an app draws objects on top of one another. It’s not uncommon to find objects being drawn that you may not have known were even in the scene.
This visualization is useful during application development for detecting layout, animation, and other operations that are graphics processing intensive.
Some other useful tips can be found in the Optimize loading XAML article.